title: Effects of intravenous lipopolysaccharide infusion on glucose and insulin dynamics in horses with equine metabolic syndrome.
abstract: OBJECTIVE
  To test the hypothesis that glucose and insulin dynamics during endotoxemia differ between healthy horses and horses with equine metabolic syndrome (EMS).
  
  
  METHODS
  6 healthy adult mares and 6 horses with EMS.
  
  
  METHODS
  Each horse randomly received an IV infusion of lipopolysaccharide (20 ng/kg [in 60 mL of sterile saline {0.9% NaCl} solution]) or saline solution, followed by the other treatment after a 7-day washout period. Baseline insulin-modified frequently sampled IV glucose tolerance tests were performed 27 hours before and then repeated at 0.5 and 21 hours after infusion. Results were assessed via minimal model analysis and area under the curve values for plasma glucose and serum insulin concentrations.
  
  
  RESULTS
  Lipopolysaccharide infusion decreased insulin sensitivity and increased area under the serum insulin concentration curve (treatment × time) in both healthy and EMS-affected horses, compared with findings following saline solution administration. The magnitude of increase in area under the plasma glucose curve following LPS administration was greater for the EMS-affected horses than it was for the healthy horses. Horses with EMS that received LPS or saline solution infusions had decreased insulin sensitivity over time.
  
  
  CONCLUSIONS
  Glucose and insulin responses to endotoxemia differed between healthy horses and horses with EMS, with greater loss of glycemic control in EMS-affected horses. Horses with EMS also had greater derangements in glucose and insulin homeostasis that were potentially stress induced. It may therefore be helpful to avoid exposure of these horses to stressful situations.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Tadros
authors.forename: Nicholas
authors.initials: N
authors.lastname: Frank
authors.forename: Fiamma Gomez
authors.initials: FG
authors.lastname: De Witte
authors.forename: Raymond C
authors.initials: RC
authors.lastname: Boston
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006734:Horse Diseases / Q000097:blood / Q000378:metabolism*; D006736:Horses; D007275:Injections, Intravenous; D007328:Insulin / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000633:toxicity*; D008297:Male
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008070:Lipopolysaccharides